Relief valve



March 11, 1952 o. L. GARRETSON 2,589,072

RELIEF VALVE Filed Sept. 20, 1948 INVENTOR.

O. l GARRETSON ATTORNEYS Patented Mar. 11, 1952 RELIEF VALVE Owen L. Garretson, Roswell, N. Men, assilmor to Phillips Petroleum Company, a corporation of Delaware Application September 20, 1948, Serial No. 50,105 6 Claims. (01. 137-53) This invention relates to valves. In a more specific aspect, it relates to relief valves which are adapted to open when the gas pressure within a. container rises above a predetermined value.

It is an object of the invention to provide an improved relief valve of the classdescribed above.

Another object is to provide a relief valve hav, ing improved operation characteristics and reduced pressure range between the pressures causing initial leak, full opening, and resetting.

Another object is to provide a strong and simplified structure whichv is adapted for use with a plurality of types of coupling attachments, and which is rugged and foolproof in operation.

Various other objects, advantages and features of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawing, in which:

The figure is a verticalsectional view of the relief valve of this invention.

This application is a continuation of the copending application of O. L. Garretson, W. R. Eddy and T. A. St. Clair, Patent No. 2,479,737, filed February 25, 1946, entitled Cylinder Filling and Dispensing Valves.

Referring now to the drawing in detail, I have shown a valve body Ill having threaded sections II and I2 at the respective ends thereof. The threaded section H is adapted to fit into a valve assembly of the type disclosed by the aforesaid Patent No. 2,479,737, and, when this connection is made, a bore l3 in the valve body communicates with a source of gas under pressure. Alternatively, the bore l3 may communicate with any other source of gas under pressure to which.

it is desired to attach the relief valve. The threaded section I2 is open to the atmosphere or, alternatively, it may be connected to a tank or other container in which the pressure is Substantially lower than the pressure within the bore 13. As still another alternative, the threaded section 12 may be attached to a stack or other vent for relief gases.

The valve body is shaped to form valve seat l5 which has a sharp annular edge It along the inner surface thereof. A valvehead assembly 17 is slidably mounted within a :bore l8 formed in the upper end of the valve seat body, and this assembly may include a generally cylindrical head member 19 having radially extending fins or ridges 20 which allow free passage of gas through the bore l8 when the valve is unseated. The head member I9 is internally threaded to receive a washer 2| which has an internally threaded opening for receiving a fusible plug 22. The plug 5 portion of washer 2|.

2 i an optional feature but is very advantageous where there is even a small chance that excessieve temperatures may be encountered. If this occurs, the fusible metal melts and allows the gas Within the bore 13 to escape, thereby preventing an XPIOS D f 1 tank th es l municating with the bore l3,

A spider 24 is s r w thr aded at he upp r d of the threaded section I 2 and this spider may b fi mly secured within an int riorly thread d pase of the section H by a soldered onn cti 25- A; compression spring 26 is fitted tween a support 21 on the spider and. the washer Z! on h valve. head. This spring is f suflicient strength to prevent unseating of the valve head until the. pressure differential between the bores l3 and I8 exceeds a predetermined value.

In accordance with the invention, a resilient washer or gasket 30 is fitted between a flanged P rtion 3| of washer 2i. and a. flan d p rtion 3.2 of head member [9. The washer 2| is also recessed, as indicated at 34, so that the gas within the bore I3 is admitted to the region or space between the resilient washer 30 and the recessed As a result, the pressure differential between recessed portion 34 and bore it forces the resilient washer 30 into engagement with the sharp ridge portion ii of the valve seat.

The operation of the relief valve will now be apparent to those. skilled in the art. Assuming that a pressure difiorential exists between bores II and I8, and that the valve is in its closed position, it will be apparent th t the valve head assembly I1 is urged into engagem nt h the alve seat by the spring 26- As lone as the pr sure diiierential betwe n the or s I 3 and I8 do s not-exceed th p edetermined value necessa y to u se t the va th as pressure in the cessed portion 34 forces resilient washer 30 against the ridge portion l6, thereby providing an effective sealing action which positively prevents the escape of gas from bore 13 into the bore l8. Higher pressures within bore I: will provide an increased pressure diiferential with the result that the resilient washer will be pressed more firmly against the valve seat as the pressure increases. Hower, wh n the pressure dif er nt al comes suflicient to overcom the force of sprin 26, the valve head is abruptly unseated and gas is vented from bore 3, to the atmosphere or a low pressure container throu h bore .18. Ac o dingly, h valve is effectively sealed at all pressures p t the critical value at which unseating oi the head assembly occurs. this sealing acti becoming more and more effective as the pressure increases With a Disc Substiggs gg tuted for Annular Washer 30 Now After (3 New After 6 Valve Months Valve Months,

Initial Leak 375 381 390 450 Full Opening 381 389 410 485 Rcscat Minimum. 372 361 325 285 The figures represent pounds per square inch, and it is to be understood that the values in the foregoing table are average values of several groups of valves which were tested.

It will, therefore, be evident that the relief valve shown is an improvement over those of the prior art and is preferable for use with liquid petroleum gas because there is less leakage before the valve unseating pressure is reached and quicker closing of the valve when the pressure drops to a safe value. The range of pressure, from full opening to reseat, with the annular washer is only.one tenth of that with the disc. The venting of an inflammable liq uid petroleum gas is the lesser of two evils, the other evil being the bursting of the tank. Therefore, the less gas vented in order to keep the tank pressure at a safe value the more valuable the relief valve is for use with liquid petroleum gas equipment.

A further advantage of the relief valve resides in the fact that the pressure of spring 26 is directed against seat through flanged portion 32 rather than through 'the gasket 30,

thereby increasing the life of the gasket and.

insuring reliable operation of the valve. Also, the undercut seat portion [5 provides a gas re: stricting passage upon unseating of thev'alve which greatly improves the popping characteristics, and accurately guides the valve head to its original seated position upon closure of the valve. This, in turn, permits larger tolerances between adjacent parts of the valve head and body, thereby minimizing the tendency for the valve to stick in closed position.

While the invention has been described in connection with a present, preferred embodiment thereof, it is to be understood that this description is illustrative only ahd is not intended: to limit the invention, the scope of which is defined by the appended claims.

I claim:

l. A relief valve comprising in combination a body having an inlet and an outlet, said body having a valve seat around said inlet, a raised edgeson said valve seat, a valve head, means urging said valve head against said seat, a resilient washer mounted on said valve head to contact said raised edge and be deformed thereby, said head being recessed behind said washer at least as far as the interior of said raised edge, guide means guiding said head inlsaid body, means to adjust the force of said urging means, said head contacting said seat'to limit deformation of said washer by said' raised edge, a conduit in said head communicating between said inlet and said outlet, a fusible plugclosing said 4 conduit and said recessed portion communicating with said inlet through said washer.

2. A relief valve comprising in combination a body having an inlet and an outlet, said body having a valve seat around said inlet, a raised edge on said valve seat, a valve head, means urging said valve head against said seat,- a resilient washer mounted'on said valve head to contact said raised edge and be deformed thereby, said head being recessed behind said washer at least as far as the interior of said "raised edge, guide means guiding said head in saidbody, means to adjust the force of said urging means, a conduit in said head communicating between said inlet and said outlet, a fusible plug closing said conduit, and said recessed portion communicating with said inlet through said washer.

3. A relief valve comprising in combination a body having an inlet and an outlet, said body having a valve seat around said inlet, a raised edge on said valve seat, a valve head, means urging said valve head against said seat, a resilient washer mounted on said valve head to contact said raised edge and be deformed thereby, said head being recessed behind said washer at least as faras the interior of said raised edge, guide means guiding said head in said body, means to adjust the force of said urging means, said head contacting said seat to limit deformation of said washer by said raised edge, and said recessed portion communicating with said inlet through said washer.

4.A relief valve comprising in combination a body having an inlet and an outlet, said body having a valve seat around said inlet, a raised edge on said valve seat, a valve head, means urging said valve head against said seat, a resilient washer mounted on said valve head to contact said raised edge and be deformed thereby, said head being recessed behind said washer at least as far as the interior of said raised edge, guide means guiding said head in said body, means to adjust the force of said urging means, and said recessed portion communicating with said inlet through said washer.

5. A relief valve comprising, in combination, a hollow elongated valve body, an annular seat formed in said valve body having a longitudinal- 1y protruding ridge portion about its inner edge, a valve head mounted for longitudinal movement in said body, said head including a flanged portion engageable with said annular seat, a resilient sealing washer disposed within said flanged portion, an annular member for holding said washer in engagement with said flange, said member having a second ridge portion of larger diameter than the ridge portion on said seat, said member engaging said washer throughout the zone extending from the washer periphery to the region of engagement of said second ridge portion, said member being spaced from the washer throughout the zone extending from the region of engagement of said second ridge portion to the inner edge of said washer thereby to define an annular chamber between said member and said washer, said annular chamber communicating with said valve body through the opening in said washer, and a spring urging said valve head into engagement with said seat portion.

- 6. A relief valve comprising, in combination, a hollow elongated valve body, an annular seat formed in said valve body having a longitudinalsaid seat dividing said valve body into an inlet conduit and an outlet conduit, a tubular valve head mounted for longitudinal movement in said body, said head being mounted in said outlet conduit and including a flanged portion engageable with said annular seat, a resilient sealing washer disposed within said flanged portion, an annular member threaded within said valve head to hold said washer in engagement with said flange, said member having a second ridge portion of larger diameter than the ridge portion on said seat, said member engaging said washer throughout the zone extending from the Washer periphery to the region of engagement of said second ridge portion, and said member being spaced from the washer throughout the zone extending from the region of engagement of said second ridge portion to the inner edge of said washer thereby to define an annular chamber between said member and said washer, said annular chamber communicating with said inlet conduit through the opening in said washer, and a spring urging said valve head into engagement with said seat portion.

OWEN L. GARRETSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 763,208 Robinson June 21, 1904 964,468 Guss July 12, 1910 1,697,516 Hale-Shaw Jan. 1, =1929 2,072,271 Meadows Mar. 2, 1937 2,111,430 Lamar Mar. 15, 1938 2,200,124 Sands May 7, 1940 FOREIGN PATENTS Number Country Date 12,911 Great Britain June 7, 1904 

